Shear thinning fluids may be useful as calibration fluids for calibrating rheometers with bob/rotor eccentricity and at lower shear rates, which may be particularly useful for calibrating rheometers at well sites that are used for measuring the rheological properties of complex fluids (e.g., wellbore fluids like drilling fluids, cementing fluids, fracturing fluids, completion fluids, and workover fluids). Additionally, high shear rate calibrations may also be performed with shear thinning calibration fluids. Newtonian fluids may be used for high shear rate calibrations in alternate of or in addition to the shear thinning calibration fluid.